[rotorwrench]

Kits are available on flea-pay to convert a standard 12-volt Delco 10si alternator to single wire 6-volt positive ground type use. They come with all the parts & instructions to do that or a person can purchase the kit to overhaul a similar modified unit for repairs. There are U-tube videos as well for this.

The caveat on these is that all of the 6-volt internal regulators put out a set 7.5-volts so they have a tendency to over charge the battery. If a person runs with headlights on then that may help with this.

These alternators were originally a 12-volt 3-wire set up. The main stud feeds the buss through an amp meter if a person wants to keep an eye on the charge state but the OEMs used the warning light that was connected to terminal #1 of the two spade terminals through a dual connector. The other terminal #2 on the dual connector was for voltage sense which would be best connected to the battery positive connector (negative ground). The voltage sense wire would help with voltage regulation and the warning light in the circuit would excite the alternator as soon as the engine started as long as the warning light went out. The other end of the light circuit connects to the ignition switch for power. To make a one wire system from them, eliminates these two features.

Instructions on the modified 6-volt units state that sometimes one of the two spade connectors (terminal #1) needs to be shorted to ground (positive ground) to get it to excite initially. After that it should do it on its own when the rpm is raised to a certain point. A lot depends on what diameter the alternator pulley is. A smaller pulley diameter will lower the rpm that excites the alternator but this may not be advisable on high rpm engines. On a model A it can use a pretty small pulley but a V8 maybe not so small.

On a 12-volt 10si or 12si negative ground unit, the terminal #1 connector of the two pin plug may have to be touched to the Main power terminal after it's all connected up to do an initial excite on an alternator with little or no residual magnetism in the rotor. This would include ones with new rotors or older ones that have set on the shelf for several years. Personally, I would connect it back up three wire style to get most efficient function out of it.